Ceramic fine bubble diffusers have been used in waste water treatment for decades. The principle involves delivering compressed air to a micro-porous ceramic plate, whereby the plate diffuses the compressed air into a tight column of fine bubbles which enters the surrounding water or waste water. The bubble column lifts water from the bottom of the water body to the surface where it gets oxygenated by the atmosphere. Additionally the surrounding water is aerated directly by gas diffusion between the bubbles and the water.
In addition to ceramic, other materials such as EPDM Rubber, Teflon and the like can be used to construct fine bubble diffusers. However, ceramic is advantageous due to its durability and enhanced overall performance. Diffuser technology has been adapted for use in lakes, ponds and other natural water bodies to provide aeration. One prior art example is a ceramic diffuser sold by Clean-Flo International, LLC. This diffuser comprises a ceramic plate epoxied, i.e. glued, to a base material, wherein a compressed air fitting is glued into the base material. In this example, the ceramic plate requires a channel to be cut into the underside of the ceramic plate to take the air from the air supply and distribute it through the ceramic plate. The channel covers less than 10% of the surface area of the underside of the plate, which results in poor overall performance and efficiency. Because the plate is epoxied to the base, only the top surface of the ceramic plate can be cleaned. Additionally, the glued-in compressed air fitting is prone to failure and breakage and cannot be replaced. Thus, because the underside of the ceramic plate cannot be cleaned or serviced effectively, the prior art diffuser will degrade over time and must eventually be discarded.
Other attempts have been made to provide improved aeration diffusers. For example, U.S. Pat. No. 7,311,299 to Sasajima discloses describes an aeration device having a rectangular elastic porous body, a support base made of an ABS resin supporting the body from below, and having an orifice for pressurized air, and a securing component which integrally secures the elastic porous body to the support base. The support base contains a portion supporting the elastic porous body from below and an attaching portion connected to the supporting portion and attaching the supporting portion to a pressurized air distribution pipe. The rectangular elastic porous body has a box shape having an opening portion, and the supporting portion being disposed in an elastic porous body.
U.S. Pat. No. 8,061,689 to Tharp relates to a flexible membrane disk diffuser having an enlarged sealing bead about the circumference of the membrane which is positioned within an annular channel on the diffuser body. A retainer ring threads onto the diffuser body to compress the sealing bead against a base surface of the channel. A discontinuity on the base surface provides a seal with the bead for the purpose of avoiding an undue tightening force of the retainer ring. The discontinuity may take the form of a ridge or a rut on the base surface of the channel.
U.S. Patent Publication No. 2002/0041041 to Johnson illustrates a ceramic diffuser assembly containing a diffuser fitting integrally connected to a diffuser body. The diffuser body contains a first ceramic layer, a second ceramic layer, and a recessed area disposed between the first and second layers. Up to four (4) ceramic layers are stated to be preferred in alternative embodiments.
U.S. Pat. No. 5,863,031 to Veeder et al. describes a gas diffuser assembly which includes a housing formed of dense impermeable ceramic material and which defines an upwardly facing recess. A fitting formed of an inert material is located in the floor of the recess for connection to a gas supply tube. A diffuser element formed of porous ceramic material is secured to the housing over the recess to define an enclosed gas chamber. The diffuser disk and the housing are adhered together with a suitable cement.
It is, therefore, to the effective resolution of the aforementioned problems and shortcomings of the prior art that the present invention is directed. However, in view of the diffusers in existence at the time of the present invention, it was not obvious to those persons of ordinary skill in the pertinent art as to how the identified needs could be fulfilled in an advantageous manner.